A number of existing uplink power control systems for satellite communication systems employ open loop power control and therefore provide no feedback to terminals or stations in the communication system regarding power levels of signals received at a satellite following transmission from the terminals or stations. Other uplink power control systems such as those described in U.S. Pat. Nos. 5,619,525 and 6,097,752 employ closed loop power control; however, the satellites are repeaters and do not generate feedback data based on received signals from terminals. In other words, these systems are bent-pipe systems whereby the satellite does not impart intelligence to the power control loops (e.g., a loop between a terminal and a satellite repeater and loop between a ground station and a satellite repeater) employed by the closed loop power system.
Existing systems do not allow stations or terminals to estimate fade sufficiently to allow for transmit power adjustment that achieves the signal quality (e.g., as measured by packet loss rates) desired when rendering broadband, multimedia satellite services such as Fixed Satellite Services (FSS) operating in the 30/20 GHz Ka-band spectrum. Ka-band transmission is affected greatly by environmental conditions such as rain, cloud cover, scintillation and interference. Accordingly, a need exists for an uplink power control system that can maintain a desired level of signal quality at the satellite in view of atmospheric fading and variation attributable to Ka-band transmission, external interference and transmission delay.